System Description - Generac Power Systems MB375 Features

MB375
OPERATING DATA
GENERATOR OUTPUT VOLTAGE/KW-60Hz
277/480V, 3-phase, 0.8 pf
600V, 3-phase, 0.8 pf
GENERATOR PARAMETERS
Subtransient Reactance
Transient Reactance
Synchronous Reactance
LOCKED ROTOR kVA %
INSTANTANEOUS DIP
Note: Available kVA values are based on instantaneous
voltage values and not sustained values. Thus a load that
requires 750 kVA will create a 20% instantaneous voltage dip
from the nominal voltage value.
COOLING
Coolant capacity
Coolant flow/min.
Heat rejection to coolant
Radiator air flow
Maximum external pressure
drop after radiator
Maximum operating air temperature
onto radiator
Maximum operating ambient
temperature
COMBUSTION AIR REQUIREMENTS
Flow at rated power
EXHAUST
Exhaust flow at rated output
Max recommended back pressure
Exhaust temperature at rated output
(pre-turbo)
Exhaust outlet size
ENGINE
Rated RPM
HP at rated kWe (gross)
Piston speed
BMEP
POWER ADJUSTMENT FOR AMBIENT
CONDITIONS
Temperature
-2.5% for every 10
Altitude
-2.5% for every 1000 m. above - m.
-2.5% for every 1000 ft. above - ft.
*Note: Values given are maximum temperatures to which power adjustment
factors can be applied. Consult your Generac representative if
operating conditions exceed these maximums.
STANDBY
kW
375
375
pu.
pu.
pu.
10%
20%
30%
35%
US gal.
60 Hz - US gal.
BTU/hr. 1,265,000
60 Hz - cfm
"H O
2
°F
°F
60 Hz - cfm
60 Hz - cfm
"Hg
°F
5" ANSI Flange
60 Hz
60 Hz
60 Hz - ft./min.
60 Hz psi
°C 25
F above - °F 77
o
Rating kW 375

SYSTEM DESCRIPTION

Multiple generators are paralleled to a common generator
bus through a unit-mounted switching mechanism to provide
MB375
the total power output. The control system consists of the
PowerManager
Rated AMP
with a PowerManager
564
375 kW genset. The PowerManager System Controller (PM-
450
SC) is provided in a separate NEMA 1 wall mount enclosure.
It interfaces with the generator controllers to provide start-
stop commands based on utility power, proportional load
sharing and provides safe paralleling of each unit to the
0.12
common generator bus.
0.13
2.98
The PowerManager Digital Control System, including
generator controllers, can be locally or remotely viewed
and programmed via Generac GenLink
400
software. PowerManager also offers upstream digital
750
communications via RS485/Modbus to other supervisory
1210
control systems.
1410
TYPICAL OPERATIONAL SEQUENCE
1. A transfer switch detects a utility failure and issues a
22
70
2. Each individual generator will start on it's own.
34,000
3. The first generator that attains rated frequency and
0.5
4. The second generator will synchronize and close into
140 *
5. When all gensets are paralleled to the bus, the PM-SC
120 *
6. If an NFPA requirement for 10 second start exists, the
1257
4237
7. If a single generator fails, load shed contacts are available
1.5
8. If load conditions are reduced (night time operation) one
1350
9. When utility supply returns, the PM-SC will issue commands
2280
555
2249
264
30 40 50
86 104 122
375 375 324
1066
3500
® Digital Control Platform (PM-DCP) along
Parallel Controller (PM-PC) for each
®
start command. The command goes to the PM-SC which
then issues a start command to the Generator Controller
(PM-DC).
voltage is connected to the common generator bus via
the switching mechanism.
the bus via its switching mechanism.
will signal the transfer switch or switches to transfer to
the load. There is a maximum of 3 programmed steps
available for connection of multiple transfer switches.
first unit up will connect to the bus. This causes the
controller in a separate emergency transfer switch to
immediately transfer to the NFPA load.
to disconnect selected noncritical loads.
generator can be programmed off-line (optional).
to transfer loads back to the utility. It then issues commands
to the individual PM-PC to disconnect from the bus. Each
PM-PC will operate its generator for the cool-down period
and then issue a shutdown command.
Communications
®